The invention relates to the readout systems for transition edge sensor (TES) microcalorimeters, highly segmented arrays of microcalorimeters and cryogenic detectors possessing very high energy resolution.
TES microcalorimeters are known for their very high energy resolution that is not limited by statistics of ionization. The attempts to take full advantage of intrinsically high energy resolution and sensitivity of this type of the detector resulted in the development of rather complex electronic readout based on implementation of SQUID magnetometers. The readout becomes too complicated especially when attempts are made to develop large imaging arrays with TES References 1, 2. The realization of readout electronics in cold cryogenic temperatures used for TES operation and implementation of frequency multiplexing technique Reference 1 to readout multiple TES do not allow to overcome problems of TES detector plane overheating as well as some other limits for the readout imposed by implementation of SQUID magnetometers. Replacing SQUID with transformer allows simplification of TES readout, however biasing of TES via implementation electronic circuitry in cold cryogenic temperatures is still complicated and prevents from building large array of TES. An ability to achieve good energy resolution with transformer readout was in question until recent time because no analysis of electronic noise contribution to TES energy resolution was made for the architecture of TES readout described below.